Listeriosis is a disease caused by the bacteria Listeria monocytogenes. Symptoms of listeriosis include vomiting, nausea, diarrhea, cramps, severe headache, constipation and persistent fever. This uncommon disease can have serious consequences for high-risk groups, such as pregnant women and their fetuses, the elderly and very young. Listeriosis is spread by consuming contaminated food or drinks. Soft cheeses, deli meats and unpasteurized milk are examples of commonly contaminated foods. For more information, see the health unit’s fact sheet on listeriosis.
Simcoe Muskoka
Ontario
Technical Notes
Simcoe Muskoka
The following graph shows the number of listeriosis cases in Simcoe Muskoka between 2000 and 2021. There have been between zero and six cases in Simcoe Muskoka every year since 2000. In 2021, there were three listeriosis cases reported in Simcoe Muskoka.
Ontario
The following graph shows the incidence rate of listeriosis in Simcoe Muskoka and Ontario between 2000 and 2021. The incidence rate in Simcoe Muskoka is comparable to the Ontario rate and both have remained low during this period. In 2021, the incidence rate for listeriosis for both Simcoe Muskoka and Ontario was 0.5 cases per 100,000 population. The Simcoe Muskoka rate has some variability which means that there are peaks and valleys and it is difficult to determine whether an increase is significant or whether it is within the expected range for this disease in these populations.
In 2008, there was a national increase in listeriosis cases when a national outbreak associated with deli meats led to the recall of more than 200 products.
More detailed data for Ontario and each health unit can be found on Public Health Ontario’s interactive Reportable Disease Trends in Ontario tool.
Technical Notes
There are many factors that influence how many cases are reported to the Health Unit, as explained on the Infectious Diseases page. It is unclear to what extent the global COVID-19 pandemic has influenced the reporting and spread of other infectious diseases – counts and rates of disease since 2020 should be interpreted with caution.
Page last updated August 19, 2022